


Explinations

by FrozenDoe



Series: Blind Faith Verse [2]
Category: Rise of the Guardians (2012)
Genre: Scientific mumbo jumbo
Language: English
Status: Completed
Published: 2015-06-14
Updated: 2015-06-14
Packaged: 2018-04-04 09:59:05
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,583
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4133295
Author URL: https://archiveofourown.org/users/FrozenDoe/pseuds/FrozenDoe
Summary: <blockquote class="userstuff">
              <p>A scientific explanation as to the creation of bucks and does and how it affects Jack and Aster. </p><p>Completely updated 5/13/16</p>
            </blockquote>





	Explinations

**Author's Note:**

> As I feel I can't properly explain in Blind Faith, here's why Aster and Jack are like they are, and why Aster treats his mate as he does.

Now, I do not have any sort of degree in genetics, just an interest and high school biology, so cut me some slack if I make a few mistakes.

As most anyone would tell you, sex is linked to the 27th pair of chromosomes in humans. X and Y chromosomes, two X's indicating female, one of each indicating male, and some combinations of up to four chromosomes indicating some state of being inter-sex. What some people may not know though, is that X and Y chromosomes are not universal. Other animals use different types of chromosomes and sex pairings that vary animal to animal, usually following some sort of pattern based on their classification. I'm using human X and Y here to make it easier to relate to. Now, I'm taking a large assumption in that the pooka follow a similar structure, two repeating chromosome indicating female and one of each indicating male. Another assumption is that in pooka the Y chromosome is a full set of genes, which is not true in humans. In humans, the Y has 59 million base pairs that make up the genetic structure while the X has 155 million. In this model, the Y will have the same amount of base pairs as the X.

So, to start the evolution, a baby pooka receives three sex chromosomes (XXY). This could have resulted from either the sperm or egg cell failing to remove half of it's genome in preparation for fertilization. Now, since the X chromosome develops faster than the Y, the fetus may have developed more feminine traits, and possibly had some combination of female and male genitalia. This would likely have been a semi-functioning penis and testicles and a possible vestigial female set that may have had any combination of a vagina, uterus, mammary glands, and or ovaries. Now, this is rather uncommon, but having an XXY sex gene set is possible in humans and is called Klinefelter syndrome.

It would have taken many sterile pooka and several thousand years, but eventually an XXY individual may have been born that either had a slightly malfunctioning Y chromosome, or had been exposed to so much of the mother's feminine hormones that the growth of the Y chromosome and the development of male sex characteristics. This could lead to limited but not impossible hermaphroditic fertility. This individual would have been capable of limited reproduction, so they likely did not attract many mates, but may have manged to attract a partner to either carry their offspring or to impregnate them. Since this individual had three possible chromosomes to pass along, it is possbile to bear a YY offspring, as well as pass along the XXY hermaphroditism that had previously not existed in the genetic pool, creating a line of XXY individuals. It is also possible that a chimera of an XY and XX zygotes formed separate genital systems, though this would not have been passed down to offspring.

After many generations, this XXY line would have had several YY babies that likely died young or in the womb, as their hormone balance was likely completely out of sync with what an XY individual would have. These YY babies would have massive amounts of testosterone and adrenaline, with very low or non-existent levels of estrogen. It wouldn't be until one or more individuals, probably through genetic recombination, gained the ablility to produce enough estrogen to survive. These first 'male bucks' as they would be called later, would also likely have difficulties breeding until, through natural selection, produced a higher level of estrogen until it reached a point where they would retain most of their testosterone and adrenaline. This likely would have been achieved through YYs being extremely strong and aggressive, so much so that they scared off XY bucks who couldn't compete with the YY who were especially constantly pumped with steroids. However, this heightened aggression would also be displayed towards their mates, possibly killing or scaring off any female they managed to court. They also likely would not be able to produce offspring that lived to term. However, once an YY appeared that had enough estrogen to temper their behavior, they would be able to fight off XYs and would not kill their mates. They also would have been able to produce a few offspring as long as the female didn't have any fertility issues. They would then mate and produce more YY babies, but these would have a larger chance of survival because of their sire's more stable Y chromosome. (The Y chromosme that produces estrogen will from here out be referred to as the eY chromosome) Their offspring, in turn, had a larger chance of survival and fertility. Eventually, through trial and error, you would have a stable, fertile population with the YY chromosome. (it may be interesting to note that as the X chromosome naturally develops faster, many mammalian infants begin life as females and as such, have nipples. Male bucks, lacking this chromosome, would not)

Going off of that, the male does would soon begin to appear. They would inherit the eY chromosome, and this would produce interesting results in their genetics. Since the eY produces estrogen as well as testosterone, the excess estrogen from the X chromosome would hinder the growth of the Y chromosome so that they developed mostly functioning ovaries and uterus, but had a vestigial penis (they may have testicles, depending on the individual, but these would not function to any degree). They have a similar build and the same instincts of the original female, due to the extra estrogen, but their vagina works a little bit differently. One of the few remaining contributions from the Y chromosome is that the vagina is malformed. They do not produce lubricant though said vagina and it is usually extremely tight, to the point where you couldn't put anything in it without severely harming the doe. Instead, they have two cervix, one in the vaginal and one in the anal cavity. The one in the anal cavity is usually covered with a mucus lining (similar to the one that covers human female cervix during pregnancy) to prevent infection, but once the doe goes into heat, the lining is shed. Meanwhile, the body would work to reuse all of what would be fecal matter in order to A. Keep the uterus free of disease and B. Keep the doe provided with extra fuel so they would go through a week long mating session. The second cervix would also likely have been a mutation, at the male does couldn't breed without it. Back on the subject of vaginas though; pregnancy hormones such as estrogen and the pooka equivalent to hCG would have caused the relaxing of the vaginal muscles, and after months of being exposed to these hormones, it would have reached a point where it would allow a relatively safe birth. It would be more painful for a male to give birth than a female as the vagina would still be tighter than normal, but it would be possible. They would also have a higher infant mortality rate as it would be harder for the offspring to be born that would go down as natural selection took it's course.

The female does are probably the easiest to explain and go like this: the female does are the original female sex. Not much to explain there. As they are not mutated at all, they would probably have the highest infant survival and fertility rates of all four sexes.

The female bucks on the other hand, are more like the mutations of the male bucks. Their code would consiste of XeY, like the male does, but there a few key differences. Oddly enough, there are very few differences genetically, it more depends on hormones and the rate of development that determines what they are. For one thing, male does are more likely to have female bucks as their testosterone would stimulate the development of the eY. Female does would have more male does since they produce more estrogen. Since no combination of parents could have one without the other, it is a toss up based on their carrier's sex. Here's an explanation of which offspring a couple could have: Male buck(YeY)/male doe(XeY): Male buck(YeY), male doe(XeY), female buck(XeY). Male buck/female doe: male doe, female buck, female doe. Female buck/male doe: Male buck, female buck, male doe, female doe. Female buck/female doe: Female buck, male doe, female doe.

As to the similarities between my use of mutations and the over used 'a wizard did it', keep in mind that genetics evolve through mutation and selective traits, despite how stupid it sounds, it would have a tiny, minuscule chance of actually occurring in their population. (Not in humans though, as Klienfelter syndrome causes sterility) Also, this would have taken place over thousands/millions of years and hundreds of generations, it didn't just magically happen in two or three. 

Also, before you ask 'what happened to the normal XY male bucks' there is an explanation for that as well. YY bucks, due to having two Y chromosomes, would have a larger amount of testosterone than their normal counterparts. This would have made them bigger, stronger, and faster than the XY, making them a better choice in mate to the not yet sentient does (they would likely have intelligence similar to a wolves at this point, smart, but not quite to the point of chimpanzees or dolphins). They also would have been far more aggressive, becoming incredibly territorial over their family and territory. In the battles over does, their larger size and greater strength would allow them to effectively crush the weaker XY bucks, preventing them from mating. The XY bucks would slowly dwindle from the population, but would likely stay alive in small numbers. (Not anymore as Aster's the last buck, and he's either YeY or eYeY depending on his parentage). Later, once they developed some sort of intelligence (chimpanzee level), the female bucks would be introduced and would be able to breed because A. Does would be slightly nervous around the hyper aggressive male bucks and B. They didn't kill each other over mates as often. They would also have a slighter build, and be faster than the bulky males, allowing them to escape alive if a male came for their mate. 

Another point that needs to be addressed is Aster's seemingly bipolar moods. The simplest answer is that he really is bipolar. The extra testosterone in him would trigger intense, often violent, outbursts and cause unstable emotions. The only way to keep him calm would be for him to be exposed to Jack or their immature offspring (a familiar Doe (friends or family) would be capable of this as well, but they’ve all been wiped out). Jack would let off pheromones that developed specifically to calm raging bucks, and his scent (especially with Aster's on top of it) would reassure him that his mate and territory remained his and there was no threat to them. However, Aster was denied access to those calming pheromones all the millennium he was alone and as such, he would be constantly aggressive and possessive due to a buildup of testosterone and no way to release it (AKA mating (also fighting, but he'd likely reached a point where no spirit would dare challenge him)). The longer they're together, the more he's exposed to the pheromones, and the calmer he'd be. He'd be far less likely to take his anger out on Jack and more likely to funnel it into protecting the doe or having (probably rough) sex with him. In Aster’s case, in addition to natural mood swings, he likely has bipolar depression from watching his entire species being wiped out by Pitch (probably PTSD as well, but as he doesn’t have flashbacks, he seems to have mostly recovered from this) 

The final point that needs to be explained is Aster’s treatment of Jack. As stated before, with the excess amount of testosterone and adrenaline male bucks have, they would be very aggressive and would want to exert that aggression in any way possible. The easiest way would be to gain complete dominance over their mate and to have sex with them as often as possible. Unconsciously, unmated bucks would seek out the most submissive does who would bend to their will and breed with them, slowly breeding submission into the new generations of does. Eventually, the extreme dominance of the bucks would be met with equal levels of submission. The more control a doe gave their mate, the safer they would be and the less likely the buck would abandon them. This isn’t to say that the does lost their personalities, they would still be themselves around their mates, but if the buck got angry or possessive for whatever reason, they would submit to calm them (the same is true of bucks, they had personalities, often times they just had short tempers). By the time they developed sentience, they would have reached a safe balance between the two. The best comparison would be that of a semi-romanticized BDSM relationship. The buck (dom) would have almost complete control over the doe (sub), but in return would take care of the doe’s needs and protect them and their eventual offspring. In order to achieve a safe, non-abusive relationship, the doe and their family would force the buck to court them, cultivating a close romantic relationship before actually mating. This would help calm down any bucks with a build up of hormones (like Aster) by slowly exposing them to their mates pheromones. In the eyes of pookan society, Jack and Aster’s relationship would classify as abusive- at least in the beginning (and by beginning I mean about fifty years after this story ends, not several months as one commenter seems to have thought)- but it would also be seen as somewhat necessary (though definitely not to the extreme Aster has taken it, that was purely the result of a hormone ridden buck who had basically lived in isolation for 9000 years and no other pooka there to protect Jack. If I ever write a sequel, I intend on addressing this particular topic and their kit's disgust with what Aster did to Jack). Jack was raised as a human in the equivalent of the 1400s-1500s (a few liberties were made to accommodate magic and spirits) and would have been raised to be a man. He would have been expected to marry a woman and order her around, while protecting and providing for her and their family. As a result, he would have been raised to be unnaturally dominate for a doe, to a point where it actually would have harmed him and his mating had he remained free of Aster’s influence(This ties back to the submissivness bred into does and the higher levels of feminine hormones). As a doe was naturally the submissive partner, the stress of not having a buck to protect him (whether they were a mate or a family member) would have led to extreme paranoia, depression, severe anxiety disorder, and in extreme cases, sociopathic behavior. Aster wasn’t making things up when they met because he was a control freak (though he is one), Jack’s mental state could have been extremely damaged due to his human upbringing after reaching adulthood, though the way Aster handled that upbringing was completely unhealthy and uncalled for.

**Author's Note:**

> I hope that explains a few things, but if you have any questions, feel free to ask.


End file.
